Welcome to the Roku Community and thanks for posting regarding using the Roku Smart Home Camera colored night vision.
Please be aware that the color night vision feature will be dependent on the surrounding light conditions. If you have the settings to dark, the Roku Smart Home Camera will not attempt color night vision and go to full night vision as there is not enough light. In addition, if you have night vision to "on" it will always go full night vision. Lastly, if the settings are turned off and mark it is not in pitch black, color night vision will be enabled.
For more information about how to change the settings regarding night vision, visit our Support page here: Use night vision on your camera or doorbell
If you have another issue in the future, please don't hesitate posting in the Roku Community again.
Roku Community Moderator